Effect of prostaglandins on rat heart sarcolemmal ATPases

1981 ◽  
Vol 59 (11) ◽  
pp. 1122-1127 ◽  
Author(s):  
M. Karmazyn ◽  
B. S. Tuana ◽  
N. S. Dhalla
Keyword(s):  
Atpase Activity ◽  
Kinetic Analysis ◽  
Enzyme Inhibition ◽  
Rat Heart ◽  
Isolated Heart ◽  
Complex Nature ◽  
Sarcolemmal Membrane ◽  
Reducing Ability ◽  
Heart Sarcolemmal Membrane ◽  
Inotropic Influences

The ability of prostaglandins (PG) D2, E1, E2, F2α and I2 (2.8 × 10−11 M to 2.8 × 10−7 M) to modify Ca2+, Mg2+ and (Na+ + K+)-ATPase activities of rat heart sarcolemmal membrane fractions was examined. Administration of PGE2, PGF2α, and PGI2 reduced basal (Na+ + K+)-ATPase activity by up to 30, 80, and 80%, respectively. PGE1 and PGD2 were ineffective at any concentration. Neither Mg2+-ATPase nor Ca2+-ATPase was affected by PG treatment. Kinetic analysis revealed that the (Na+ + K+)-ATPase activity reducing ability of PGE2, PGF2α and PGI2 was of a complex nature involving a reduction in Vmax and an elevation of the respective K values for either substrate or activator. These results demonstrate that some PG's are potent inhibitors of rat heart (Na+ + K+)-ATPase. These PG's produced varied inotropic influences on isolated heart preparations and it is uncertain whether their myocardial actions are dependent on enzyme inhibition.

Characterization of the binding of [3H]SR 33805 to the slow Ca2+ channel in rat heart sarcolemmal membrane

1994 ◽  
Vol 267 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Pierre Chatelain ◽  
Philippe Dewinkeleer ◽  
Philippe Beaufort ◽  
Louis Meysmans ◽  
Martine Clinet
Keyword(s):  
Rat Heart ◽  
Sarcolemmal Membrane ◽  
Heart Sarcolemmal Membrane

Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

1992 ◽  
Vol 2 (2) ◽  
pp. 105-111 ◽  
Author(s):  
S. Sánchez-Nieto ◽  
R. Rodríguez-Sotres ◽  
P. González-Romo ◽  
I. Bernal-Lugo ◽  
M. Gavilanes-Ruíz
Keyword(s):  
Zea Mays ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Atpase Activity ◽  
Kinetic Analysis ◽  
Atp Hydrolysis ◽  
Membrane Atpases ◽  
Substrate Concentrations ◽  
Tonoplast Atpase ◽  
Specific Inhibitors

AbstractThe effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low (0.77mm) ATP concentrations.

scholarly journals Chemical aspect of the influence of cobalt ions on atpase activity

2000 ◽  
Vol 65 (7) ◽  
pp. 507-515 ◽  
Author(s):  
Ljubica Vujisic ◽  
Danijela Krstic ◽  
Jovan Vucetic
Keyword(s):  
Experimental Data ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Kinetic Analysis ◽  
Synaptic Plasma Membrane ◽  
Cobalt Ions ◽  
Dependent Inhibition ◽  
Ic50 Values ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

The influence of Co 2+ ions on the activities of Na+/K+-ATPase and Mg2+ -ATPase, enzymes from rat brain synaptic plasma membrane, was studied. The aim of this study was to investigate the inhibition of both ATPases activities byexposure tocobalt ions as a function of experimentally added CoSO4. The "free" Co2+ concentrations in the reaction mixturewere also calculated and discussed. CoSO4 induced a dose-dependent inhibition of both enzymes. The IC50 values of Co 2+, as calculated from the experimental curves, were 168 mM for Na+/K+-ATPase and 262 mMfor Mg 2+-ATPase, and for the recalculated free Co 2+ concentration 75.4 mM for Na+/K+-ATPase and 136 mM for Mg 2+-ATPase. The obtained linear Dixon's plot for Na+/K+-ATPase implies equilibium binding of cobalt with inhibitory sites on the enzyme. The kinetic parameters for both enzymes in presence and absence of CoSO4 were calculated from the experimental data. The results of the kinetic analysis show that inhibition of Na+/K+-ATPase induced by CoSO4 is non-competitive, and for Mg 2+-ATPase that there are two sites of different sensitivities or two different enzymes.

Angiotensin II type 2 receptor blocker PD123319 has more beneficial effects than losartan on ischemia–reperfusion injury and oxidative damage in isolated rat heart

2019 ◽  
Vol 97 (12) ◽  
pp. 1124-1131 ◽  
Author(s):  
Aysu Kilic ◽  
Savas Ustunova ◽  
Cansu Usta ◽  
Huri Bulut ◽  
Ismail Meral ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Rat Heart ◽  
Ischemia Reperfusion Injury ◽  
Isolated Heart ◽  
Ischemia Reperfusion ◽  
Isolated Rat Heart ◽  
Albino Rats ◽  
Partial Recovery ◽  
Treatment Groups ◽  
All Treatment

Our study aimed to determine the effects of losartan and PD123319 in ischemia–reperfusion (IR) injury in isolated perfused rat heart. The study used 40 male Wistar albino rats that were grouped as Control, IR, and IR treatment groups that received losartan (20 mg/kg), PD123319 (20 mg/kg), and losartan+PD123319. The hearts were attached to Langendorff isolated heart system by employing in situ cannulation method, and cardiodynamic parameters were recorded during the experiment. At the end of experiment, hearts were retained for biochemical analysis and all data were statistically evaluated. A partial recovery of cardiodynamic parameters was observed in all treatment groups. A significant increase in oxidative stress parameters were seen in the IR group, whereas all treatment groups exhibited lower increase. Furthermore, levels of all antioxidant parameters were significantly lower in the IR group, but higher in the treatment groups. Effects on all parameters were much more remarkable in the PD123319 group. Levels of angiotensin II and renin were increased (P < 0.001) with IR application and decreased (P < 0.001) with the treatment of both antagonists. In conclusion, treatment of losartan and PD123319 played a cardioprotective role against IR injury, PD123319 being more effective in this protection.

Maximum heart rate of soricine shrews: correlation with contractile properties and myosin composition

1992 ◽  
Vol 262 (5) ◽  
pp. R842-R851 ◽  
Author(s):  
M. Vornanen
Keyword(s):  
Atpase Activity ◽  
Body Mass ◽  
Small Mammals ◽  
Rat Heart ◽  
Common Shrew ◽  
Electrophoretic Analysis ◽  
Myosin Atpase ◽  
Wild Mammals ◽  
Myosin Atpase Activity ◽  
The Common

Maximum heart rates (HR) of three soricine shrews and six other small mammals were measured in response to a single supramaximal dose of isoproterenol (Iso) under urethan anesthesia. The highest HR, 1,043 +/- 66 (SD) beats/min (n = 3), was in least shrew (Sorex minutus, mean body mass 3.02 +/- 0.81 g). Maximum HRs of common shrew (Sorex araneus, 7.16 +/- 1.54 g) and water shrew (Neomys fodiens, 12.80 +/- 1.54 g) were 938 +/- 29 (n = 7) and 887 +/- 21 (n = 6), respectively. In general, maximum HRs of soricine shrews and other small wild mammals followed the common mammalian pattern, fHmax/Iso = 443 x Mb-0.14, determined by body size. The exponent for this equation is smaller than that of resting HR (-0.25) (Stahl, J. Appl. Physiol. 22: 453-460, 1967), predicting crossover at approximately 3 g body mass. However, resting HRs of small mammals were clearly lower than expected on the basis of body mass. Lowering resting HR below the common mammalian level, with concomitant increase in stroke volume, seems to be a prerequisite for small mammals to regulate cardiac output against the ceiling of maximum HR. Electrophoretic analysis showed that the myosin of shrew ventricles is different from those of rodent species. In native conditions, shrew myosin, designated V1', migrated faster than the V3 and V1 forms of rat heart. On SDS gradient gel the single heavy chain of shrew myosin migrated slower than the alpha- or beta-chains of rat ventricle. Differences in the molecular weight of light chains were also noted between small mammals. Despite the notable differences in myosin composition, myosin-ATPase activity of the shrew hearts was similar to that of mouse and rat heart. Because duration of isometric contraction was inversely related to resting and maximum HRs, it was concluded that in the small mammals rate and duration of contraction are determined mainly by the release and uptake rate of myoplasmic Ca2+ and less by myosin-ATPase activity.

Lack of effect of prostaglandins on rat heart myofibrillar ATPase activity

1981 ◽  
Vol 6 (6) ◽  
pp. 633-639
Author(s):  
G.N. Pierce ◽  
M. Karmazyn ◽  
M.J. Daly ◽  
N.S. Dhalla
Keyword(s):  
Atpase Activity ◽  
Rat Heart ◽  
Myofibrillar Atpase ◽  
Myofibrillar Atpase Activity

Seasonal variations in properties of rat heart mitochondria: Effect on membrane fluidity and ATPase activity in diabetes

2008 ◽  
Vol 44 (4) ◽  
pp. 788 ◽  
Author(s):  
Jana Mujkosova ◽  
Miro Ferko ◽  
Iva Waczulikova ◽  
Michal Zeman ◽  
Monika Okuliarova ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Membrane Fluidity ◽  
Seasonal Variations ◽  
Rat Heart ◽  
Heart Mitochondria ◽  
Rat Heart Mitochondria

scholarly journals Angiotensin Converting Enzyme Inhibition Decreases Cell Turnover in the Neonatal Rat Heart

2002 ◽  
Vol 52 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Jeong Hoon Choi ◽  
Kee Hwan Yoo ◽  
Hae Won Cheon ◽  
Kyung Burm Kim ◽  
Young Sook Hong ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Enzyme Inhibition ◽  
Rat Heart ◽  
Neonatal Rat ◽  
Angiotensin Converting Enzyme Inhibition ◽  
Converting Enzyme ◽  
Cell Turnover ◽  
Converting Enzyme Inhibition ◽  
Neonatal Rat Heart
Sign in / Sign up

Export Citation Format

Share Document